Vulnerability in libtiff (CVE-2026-18495)
Summary
Vulnerability in libtiff (CVE-2026-18495). Risk of unauthorized operations or information disclosure. Exploitable via tiff2pdf.
Original description
The description as published by the source.
A flaw was found in libtiff. A heap-buffer overflow vulnerability exists in the tiff2pdf utility due to an integer truncation error when processing crafted BigTIFF files. An attacker can provide a specially crafted BigTIFF file, causing a 64-bit StripByteCounts value to be truncated to a 32-bit integer. This leads to an undersized memory allocation and a subsequent out-of-bounds memory copy, resulting in a crash and severe memory corruption.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-18495 has been found in libtiff.
Attackers can target a specific entry point like tiff2pdf over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "libtiff CVE-2026-18495" on the vendor's site.
CVE-2026-18495 (libtiff) — CWE-122 / CVSS v3 6.1
Attack vector: local
Attack surface: tiff2pdf / StripByteCounts
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-122) exists in libtiff. Attackers reach the vulnerable code path via tiff2pdf.
Check the vendor advisory for the affected versions of libtiff. Attack surface: tiff2pdf / StripByteCounts.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'libtiff' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'libtiff' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
libtiffを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-18495 gdal
References
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web secalert@redhat.com
- web nvd.nist.gov
- web github.com